Signaling system



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. I =smnanmcsrsram v I I n s nmwne, West Actom'London', m,

9 land, assignor to Electric & M

mica! Limited, Hayeadmddlesex, E'nflandytwm.

panyotGreatBritaln v InG ' Application in which a plurality of cameras arearranged to I 1 feed picture signals to a commonpicture channel. a In the production of television programmes,

it is usual to employ a number of. television'cameras each viewing adifierent portion of the "set" which is to be televised and. to feed picture 'signals from difierent cameras into a common pic- I I ture channel under the control of the producer,

so. that a variety of close-up andlong shots from I diflerent angles may be presented to the viewer. 'When' more than one settisin use, a considerable number of cameras may belnvolved, and additionalcameras may also be required to pro- The' producer is usually provided withaxcon- March 30, 1940, an; maxim 1: feat Britain aiars, 19 9- I a a a marine intended. a

It istheobiect of, eliminatethe' necessityior the actuation ofa vthe namerot the particular operator ior'whom I selected key in order to. put the producer in communication with the: operator of the camera which isieeding, oris about to feed. picturesignals too common picture channeland so to overcome the. above mentioned disadvantages; "1

provided :aftelevision system comprising a plu- 1 rality i 'of/ television cameras, {a control unit for 'vide background shots or even film sequences; I 3

trol unit having control means, such as poten I tiometer, which enables him to control the I amplitude of the picture signals, led by each camera into the common picture channel from'zero to maximum value In addition, the producer is I usually provided with a'microphone and a series of switches. which 'enable' him to speak tothe camera operators either individually or collectively in order to issue instructionsin regard to I the dispositions of the'came'ras. Thus,in'case :said cameras said control having: separate control meansfi'or controllingthe picturesignals fed'by'each of said cameras to a common channeland furthermeans so associated with each of said control means that on'adjustment'of one of said ccntrolmeansto a predetermined position, said further nieans'is also actuated so as to place the operator of said control unit in communication -with-the operator :01 the camera associated with a i'ader switch said adjusted control means.

Preferably, said control means is "and said predetermined position is any position ofa' system having sixcame'rasthe producer is usually provided with a control, unit having six. control means, or faders, one for each' camera channel and six keys' for switching his microphone into circuit with each of thecamera operators,.-together with f'an additional so called omnibuskey for switching, his microphone into circuit with all the camera operators simultane-" ously. The producer thus has to select a partic-- ular key' in order to put himself in communicae tionwith the operatorv oi the camera, the signals from which he is'about to feed into the common channel, and as he'has at such-times to control in which said one of said cameras is arranged to feed-its picture "channels to said common channel. Said communication; may be-eiIected by placing amicrophone. at said ,control unit in ciri cuit with a telephone at said camera. -Iidesired, gsaid control unit may beprovided with an initial range of adjustment preceding the range of adjustment which controls said picture signals, and

I when adjusted within the saidinitial range connects said microphone, o'rL-a source of warning signals, to said telephone.

I Byway of example one form oi the invention will, now be described with reference to the acschematic circuit arrangement, and a few "me-- the output from one or morecommon channels it is a matter of difliculty for him also to select 7 the appropriate key, with the result that inpractice the omnibus key is usually employed instead,

and the producer is constantly in communication with the'operators of all the cameras. The 7 use of the omnibus key inthis manner has two disadvantages. Firstly, each camera operatoris compelled to listen'to the instructions intended for each of the cameraioperators, and as a result the operators are liable to become less alertvand to fail to act upon the producers'instructions promptly when their cameras are feeding sig-- 3-;11818 to the camera picture channel. Secondly,

the producer has to couple companying drawing .a .which showsa,genera1 chanical'details 0fthls example of theinvention. Inthejdrawing I, 2 and 3 arethespindlesof three iader switchesjl, 33 and "each of which controls, the transmission picture signals from its associated televislon'cameras II, "and 2I.

to a common picture channel 4|, and id are fixed to the spindles I I and Irespectively, andv are ;.arranged to actuate associ- 'ated switches 4. Itwill lie-observed thateach of the cams la, la and lahas a circular contour with a flat portion J such that the switches 4 are open when said flat-portion 9 is in contact with a one oi the switch arms (see-the switchesasso ciated with cams-2a and 3a) ,'but"are closedwhen I their associated spindles i, 2 and l are rotated his instructions'with 5 so as'to'move said'ilat' portion away from said the present invention to. I J

ccording to the'present invention, there' is- I switch arm (see the switch associated with the cam in). The angular position oi said cams la, la and in upon the spindles I, 2 and 3 is so arranged that when said flat portions are in contact with said switch arms and said switches are open, each of said fader switches is adiusted so that no output is fed from the camera associated therewith to the common output channel, but when any one of said iader switches is retated so as to cause its associated camera to feed signals to said common channel, the switch associated therewith is closed.

Each of the switches 4 is connected in a circuit comprising the battery 8 and one of the relay windings III which controls a switch ll serving to connect one of the camera telephones I! to the output from the microphone l4 on. the control unit. When any one of the fader switches is adjusted so as to cause its associated camera to feed signals to the common output channel, the switch 4 associated therewith is closed, the corresponding relay winding III energised by the battery 8 and the telephone l3 of said camera connected to the output from the microphonea visible indication to the operator at the control unit and the operator at said camera that said camera is feeding signals to said common channel.

A so-calledomnibus key l5 may also be pro-' vided on the control unit to enable the operator to get into communication with all the camera operators simultaneously, when said key I5 is depressed, it mechanically operates switches which connect all the telephones [3 to the output of the microphone as will be seen from, the drawing.

It may also be desirable for the operator of the control unit to get into communication with the operator of a camera before signals from said camera are fed into said common channel so that said operator may be warned that his camera is about to be connected with said chan-, nel. This may be done by allowing said spindles I, 2 and 3 a small initial range of adjustment within which their associated fader switches are not adjusted, so that any one of said spindles may be first rotated through a small angle to operate the switch 4 and thus to put the operator of the control unit in communication with the operator of the camera associated therewith before signals from saidcamerai are fed into the common channel.

If it is not necessary to give verbal instructions to the camera operator, a warning signal will be suflicient and in this casethe arrangement which has been described above with reference to the drawing may be retained and additional circuits provided to feed a warning signal, such as an audio frequency alternating current, to the telephones IS on any camera which is about to be put into operation. The additional circuit may comprise a source of audio frequency alternating current arranged to be connected to the telephones l3 by further switches similar to the switches 4, an additional cam being provided on each of the spindles I, 2 and 3 and arranged to close said further switches momentarily during the initial range of adjustment of the spindles preceding the ldiustment oi the associated iader switches.

Alternatively, a push button or like switch maybeassociated witheachoitheiaderswiteh controls and arranged so that when it is actuated by the operator'it sounds the warning signal in the telephones associated with the corresponding camera.

Although the invention has been described with reierence to three cameras, it will be appreciated that it may be used with any number of cmeras, some of which may be set up to view "sets," others to view still pictures and others to view film sequences.

It is also to be understood that althoushthe invention has been stated to relate to a television system, it is not limited to television systei'n's in which the picture signals from the camera are .fed to a common channel and are transmitted either by a cable or radio link to a cathode ray tube or other reproducer. to reproduce the scenes viewed by said cameras, but also includes television systems in which said signals are recorded upon a record such, for example, as a motion picture film, which may subsequently be used to reproduce said scenes.

I claim: Y

1.' A signaling system comprising a plurality of television cameras, each oi said cameras having a video output circuit, a common television channel, a central control unit for said cameras, said unit including means for selectively connecting one of said output circuits to said channel, a separate instruction signaling channel connected from said control unit to each of said cameras for carrying information from said control unit to said cameras, and switching means actuated by said selective connecting means for energizing the signaling channel associated with the selected output circuit.

2. A signaling system comprising a plurality of television cameras, each of said cameras having a video output circuit, a 'common television channel, a central control unit for said cameras, said unit including means for selectively connecting one of said output circuits to said channel, a separate instruction signaling channel connected from said control unit to each of said cameras for carrying information from said control unit to said cameras, switching means actuated by said selective connecting means for energizing the signaling channel associated with the selected output circuit, and independent switching means for energizing allof said signaling channels simultaneously.

3. A signaling system comprising a plurality of television cameras, each of said cameras having a video output circuit, a common television channel, a central control unit for said cameras, said unit including means for selectively connecting one of said output circuits to said channel, a separate instruction signaling channel connected from said control unit to each of said cameras for carrying information from said-control unit to said cameras, switching means actuatedby said selective connecting means for energizing the signaling channel associated with the selected output circuit, independent switching means for energizing all of said signaling channels simultaneously, and means at each of said cameras and said central control 'unit actuated '-by said selecting means to provide an indication of the selected camera and selected signaling channel. 1

. CECIL OSWALD BROWNE. 

